Adaptive transmission controls are, for example, known from U.S. Pat. No. 5,157,609 and German patent publication 4,136,613 as well as from the articles from xe2x80x9cAutomobiltechnische Zeitschriftxe2x80x9d 94 (1992) 9, starting at page 428 and from xe2x80x9cAutomobiltechnische Zeitschriftxe2x80x9d 95 (1993) 9, starting at page 420. In automatic transmissions, the transmission changes are, in general, determined in dependence upon the vehicle longitudinal speed and the engine load (throttle flap angle). This takes place by means of a characteristic field. In adaptive transmission control systems, the characteristic field can be adapted to the behavior of the driver (driver type), the traffic situation and/or to the driving situation to which the vehicle is subjected. The transmission ratio changes are determined by means of the characteristic field. In setting the behavior of the driver, it is generally evaluated whether the driver adheres more to a driving-power orientated driving manner or more to a fuel optimized driving manner. In the evaluation of the traffic and driving situation, it can be distinguished, for example, whether the vehicle is in city traffic, ahead of or in a curve, on a hill or in overrun operation. Depending upon the evaluation of the above-mentioned points, the particular characteristic line which is suitable is selected from a number of different characteristic lines. Furthermore, a shifting of the base shifting characteristic field, as described in U.S. Pat. No. 5,857,161, can be provided.
In the known state of the art, for recognizing the type of driver, it is suggested to arrive at different types of estimation of the instantaneously present type of driver by means of different algorithms (for example, start-up evaluation, gradient evaluation). These estimates are then collected and processed to an instantaneous valid type of driver, for example, via maximum formation, weighted and/or sliding sum formation. In this processing, the above-mentioned various types of estimation are prioritized differently.
Reference can also be made to U.S. Pat. No. 6,216,077.
Furthermore, a hierarchially structured control of the elements of the drive train of a motor vehicle is known from U.S. Pat. No. 5,351,776. The drive train includes, for example, the engine, clutch/torque converter, transmission.
In electronic transmission controls (GS), it is therefore conventional to make the selection of the particular gear to be engaged in a stepped automatic transmission (AT) or in an automated shift transmission (ASG) on the basis of a plurality of criteria. The in part contradictory requirements of the criteria (for example, minimizing of the fuel consumption in contrast to high Dower reserve) can be considered via a prioritization which is dependent upon the driving state, driver command and the driving situation. Furthermore, situation-caused shifting restraints have to be considered. Here, a series of problems results. Accordingly, it is difficult to integrate new criteria because this brings with it a change of the already existing program code. The prioritization is partially directly hidden in the code. For this reason, it is difficult to adapt the prioritization to continuously changing requirements. In this way, the overview is missing which is needed for applying the prioritization.
The invention relates to an advantageous breakdown of the criteria in individual aspects and the sequence of the gear selection which results therefrom. This gear selection avoids the disadvantages and is a partial result of an object orientated analysis of the transmission control.
The system of the invention for adjusting a transmission ratio in a transmission built into a motor vehicle includes: at least two transmission criteria with which first transmission ratios are determined on the basis of at least two different determination modi; and, first means by means of which a second transmission ratio is selected in accordance with a pregivable prioritization from the determined first transmission ratios. The transmission ratio is then adjusted in dependence upon the selected second transmission ratio.
In an advantageous embodiment of the invention, second means are provided with which the second transmission ratio is modified in accordance with a pregivable strategy. The transmission ratio is then adjusted in dependence upon the modified second transmission ratio.
In a further embodiment of the invention, with the second means: a change of the adjusted transmission ratio is determined in dependence upon the instantaneous adjusted transmission ratio and the selected second transmission ratio; a check is made in accordance with a pregivable strategy as to whether the determined change is permitted; and, an adjustment of the transmission ratio in accordance with the determined change (HSV, REV, DHSV, DRSV) is only then undertaken when this change is permissible.
Here, it can be provided that the modification or the check of the permissibility of the change takes place in dependence upon the transmission ratio criterion which forms the selected second transmission ratio.
The determined changes can be upshifting operations, downshifting operations, double upshifting operations and/or double downshifting operations and/or pregivable multiple upshifting and/or multiple downshifting operations.
Furthermore, it can be provided that at least one transmission ratio criterion contains at least two shift characteristic lines which can be distinguished via pregivable codes.
In an especially advantageous embodiment of the invention, it is provided that the transmission ratio criteria and the first means for transmitting the first transmission ratios communicate via a criteria administrator. This affords a very simple applicability. Here, the first means communicate with the transmission ratio criteria by means of the criteria administrator via pregiven identification codes.